Of the 90 players who started training camp with the Jaguars last month, 31 were rookies, including 23 who were undrafted.

A few, like running back Lonnie Pryor and tight end Ryan Otten, were priority signings for the Jaguars hours after the draft concluded in April.

But the road to a roster spot for many of the other undrafted rookies — particularly safety Ray Polk, receiver Jamal Miles and linebackers Michael Zimmer and Maalik Bomar — will be more difficult. Heading into Friday’s preseason opener against Miami, all four find themselves at the bottom of the depth chart.

When practice started July 26, no Jaguars player was more surprised to be on the field than Polk.

The Jaguars claimed Polk off waivers from Seattle a day before players reported. Before hearing from Jacksonville, the former Colorado player was searching for a new job, possibly even one out of football.

“I didn’t know what the next step in life would be, whether I would get a 9-to-5 job or a part-time job and keep pursuing [an NFL career],” Polk said. “You could always be at home thinking about what the hell you are going to do in life, but fortunately I got the call from Jacksonville, and now I’m here.”

Polk was at home in Arizona when he was claimed by the Jaguars. He scrambled to get the essentials together and made a 3:30 p.m. flight to the East Coast, less than 24 hours before coach Gus Bradley’s first meeting of camp.

Polk arrived in Jacksonville — his first trip to Florida — about 1:30 a.m. on July 25 and the roller coaster has not stopped since.

“Between camps with Seattle, I photocopied a bunch of formations and stuff, and I brought that here and just started studying as soon as I got the playbook,” Polk said. “That’s pretty much all I do. I turn my phone off during the day, and I’m back in the playbook.”

While entering training camp with a new team can be daunting, Polk found relief in the form of two friendly faces: Pryor and receiver Toney Clemons.

Pryor and Polk trained together during the offseason; Clemons was his teammate at Colorado, where Polk, now listed as 6-foot and 219 pounds, finished his career with 237 tackles and eight pass breakups.

“That’s my man; I watched Ray grow,” Clemons said. “He was always a real active guy, real ball-hawking and energetic. I’m glad we have him. He is big. He’s strong, fast and athletic. We always matched up well, even in college. To have him on this level, it is good to see.”

Despite his impressive physical attributes, Polk landed on the wrong end of a tongue lashing from Bradley last week. Polk struggled to get positioned properly during 11-on-11s.

With only a limited amount of time to make a good impression on the coaching staff, Polk knows he has to make smarter, quicker decisions.

“I’ve just got to get on the right page as a safety and make the calls that need to be made,” he said after the incident.

The first mandatory series of roster cuts is Aug. 27, when all NFL teams reduce their roster to 75 players. Four days later, another mandatory reduction cuts each roster to 53 players.

Polk’s hesitation is not uncommon for rookies. Zimmer, an undrafted linebacker from Illinois State, said reaching the point where instincts take over is critical to being successful.

However, the sheer amount of information required to be learned in a short time can crowd a player’s mind, meaning there is more thinking than simply reacting.

“The playbook is a lot more complex than anything I have ever really been around,” said Zimmer, a former first-team All-Missouri Valley selection.

Zimmer is likely third on the depth chart at middle linebacker behind starter Paul Posluszny and LaRoy Reynolds, an undrafted free agent from Virginia who has flashed during camp.

When faced with more detailed terminology or a foreign look from the offense in 7-on-7s or 11-on-11s, Zimmer said he turns to Posluszny and Russell Allen for assistance.

Remembering the apprehension that came with his first training camp, Posluszny has gravitated toward being a mentor to Zimmer and several other inexperienced defensive players.

“It’s tough because we are installing a lot of defenses, and it is very different from what you played in college,” said Posluszny, who first entered camp with Buffalo in 2007. “It’s a challenge for a young guy to come in and do well right away. As a veteran, you have the opportunity to teach young guys, especially when you have been around a certain group before. That’s part of being a veteran.”

Miles, who played at Arizona State, has spent time following the lead of Cecil Shorts, the de facto veteran leader of the Jaguars’ receiving unit.

Miles was an explosive threat for the Sun Devils, setting a school record with 1,866 career kick return yards, including four touchdowns, while also playing wide receiver. Now, he relishes each opportunity he is given.

Following last Monday’s practice, Shorts, Miles and a handful of other receivers hauled in throws from quarterback Matt Scott — also an undrafted rookie — before catching balls launched from a machine. The group has repeated the process several times during camp.

“It’s not so much about trying to get noticed [by the coaching staff], but it’s about trying to perfect my craft and get better every day,” Miles said of spending extra time on the practice field. “Cecil is pretty much the leader of our receiving group. We follow what he does. If he wants to catch balls after practice, we basically follow in his footsteps.”

Additional work after practice is often necessary when a team uses the ability to have a full 90-man roster at this point in camp. So many players means few reps for those at the bottom of the depth chart still hoping to make an impact.

Capitalizing on an opportunity, no matter how small it is perceived, could be the difference in being cut or staying on the roster for another day.

Bomar played at Cincinnati and is working at outside linebacker, mostly with the third-team.

“Speaking for all the guys, coming in here, you have to have that hunger,” he said.